Abstract
Although many publications have appeared in recent years purporting to address the economics of conservation of biodiversity, most do not address the diversity issues as such. This shortcoming appears only to have been recognized recently. Furthermore, from the literature it is clear that natural living areas — apart from conserving biodiversity — jointly give rise to other conservation benefits, and therefore, their conservation needs to be evaluated holistically.It is suggested that when constraints are placed on available resources for biodiversity conservation, some criteria for species preservation such as those associated with SMS (safe minimum standard) may exhibit unsatisfactory features. While imperfection of knowledge is a serious limitation on rational decision-making about conservation of biodiversity, we have some knowledge and we may be able to use that to determine rational probabilities. In addition, it is important to scrutinize ecological claims about biodiversity. For example, ecosystems containing greater biodiversity may not be more sustainable than those with less diversity. It is also argued that the SMS criterion needs further development because there may be no standard which ensures the survival of any species.